Source: \core\renderers\webgl\utils\RenderTarget.js
import { Rectangle, Matrix } from '../../../math';
import { SCALE_MODES } from '../../../const';
import settings from '../../../settings';
import { GLFramebuffer } from 'pixi-gl-core';
/**
* @class
* @memberof PIXI
*/
export default class RenderTarget
{
/**
* @param {WebGLRenderingContext} gl - The current WebGL drawing context
* @param {number} [width=0] - the horizontal range of the filter
* @param {number} [height=0] - the vertical range of the filter
* @param {number} [scaleMode=PIXI.settings.SCALE_MODE] - See {@link PIXI.SCALE_MODES} for possible values
* @param {number} [resolution=1] - The current resolution / device pixel ratio
* @param {boolean} [root=false] - Whether this object is the root element or not
*/
constructor(gl, width, height, scaleMode, resolution, root)
{
// TODO Resolution could go here ( eg low res blurs )
/**
* The current WebGL drawing context.
*
* @member {WebGLRenderingContext}
*/
this.gl = gl;
// next time to create a frame buffer and texture
/**
* A frame buffer
*
* @member {PIXI.glCore.GLFramebuffer}
*/
this.frameBuffer = null;
/**
* The texture
*
* @member {PIXI.glCore.GLTexture}
*/
this.texture = null;
/**
* The background colour of this render target, as an array of [r,g,b,a] values
*
* @member {number[]}
*/
this.clearColor = [0, 0, 0, 0];
/**
* The size of the object as a rectangle
*
* @member {PIXI.Rectangle}
*/
this.size = new Rectangle(0, 0, 1, 1);
/**
* The current resolution / device pixel ratio
*
* @member {number}
* @default 1
*/
this.resolution = resolution || settings.RESOLUTION;
/**
* The projection matrix
*
* @member {PIXI.Matrix}
*/
this.projectionMatrix = new Matrix();
/**
* The object's transform
*
* @member {PIXI.Matrix}
*/
this.transform = null;
/**
* The frame.
*
* @member {PIXI.Rectangle}
*/
this.frame = null;
/**
* The stencil buffer stores masking data for the render target
*
* @member {glCore.GLBuffer}
*/
this.defaultFrame = new Rectangle();
this.destinationFrame = null;
this.sourceFrame = null;
/**
* The stencil buffer stores masking data for the render target
*
* @member {glCore.GLBuffer}
*/
this.stencilBuffer = null;
/**
* The data structure for the stencil masks
*
* @member {PIXI.Graphics[]}
*/
this.stencilMaskStack = [];
/**
* Stores filter data for the render target
*
* @member {object[]}
*/
this.filterData = null;
/**
* The scale mode.
*
* @member {number}
* @default PIXI.settings.SCALE_MODE
* @see PIXI.SCALE_MODES
*/
this.scaleMode = scaleMode !== undefined ? scaleMode : settings.SCALE_MODE;
/**
* Whether this object is the root element or not
*
* @member {boolean}
*/
this.root = root;
if (!this.root)
{
this.frameBuffer = GLFramebuffer.createRGBA(gl, 100, 100);
if (this.scaleMode === SCALE_MODES.NEAREST)
{
this.frameBuffer.texture.enableNearestScaling();
}
else
{
this.frameBuffer.texture.enableLinearScaling();
}
/*
A frame buffer needs a target to render to..
create a texture and bind it attach it to the framebuffer..
*/
// this is used by the base texture
this.texture = this.frameBuffer.texture;
}
else
{
// make it a null framebuffer..
this.frameBuffer = new GLFramebuffer(gl, 100, 100);
this.frameBuffer.framebuffer = null;
}
this.setFrame();
this.resize(width, height);
}
/**
* Clears the filter texture.
*
* @param {number[]} [clearColor=this.clearColor] - Array of [r,g,b,a] to clear the framebuffer
*/
clear(clearColor)
{
const cc = clearColor || this.clearColor;
this.frameBuffer.clear(cc[0], cc[1], cc[2], cc[3]);// r,g,b,a);
}
/**
* Binds the stencil buffer.
*
*/
attachStencilBuffer()
{
// TODO check if stencil is done?
/**
* The stencil buffer is used for masking in pixi
* lets create one and then add attach it to the framebuffer..
*/
if (!this.root)
{
this.frameBuffer.enableStencil();
}
}
/**
* Sets the frame of the render target.
*
* @param {Rectangle} destinationFrame - The destination frame.
* @param {Rectangle} sourceFrame - The source frame.
*/
setFrame(destinationFrame, sourceFrame)
{
this.destinationFrame = destinationFrame || this.destinationFrame || this.defaultFrame;
this.sourceFrame = sourceFrame || this.sourceFrame || destinationFrame;
}
/**
* Binds the buffers and initialises the viewport.
*
*/
activate()
{
// TOOD refactor usage of frame..
const gl = this.gl;
// make sure the texture is unbound!
this.frameBuffer.bind();
this.calculateProjection(this.destinationFrame, this.sourceFrame);
if (this.transform)
{
this.projectionMatrix.append(this.transform);
}
// TODO add a check as them may be the same!
if (this.destinationFrame !== this.sourceFrame)
{
gl.enable(gl.SCISSOR_TEST);
gl.scissor(
this.destinationFrame.x | 0,
this.destinationFrame.y | 0,
(this.destinationFrame.width * this.resolution) | 0,
(this.destinationFrame.height * this.resolution) | 0
);
}
else
{
gl.disable(gl.SCISSOR_TEST);
}
// TODO - does not need to be updated all the time??
gl.viewport(
this.destinationFrame.x | 0,
this.destinationFrame.y | 0,
(this.destinationFrame.width * this.resolution) | 0,
(this.destinationFrame.height * this.resolution) | 0
);
}
/**
* Updates the projection matrix based on a projection frame (which is a rectangle)
*
* @param {Rectangle} destinationFrame - The destination frame.
* @param {Rectangle} sourceFrame - The source frame.
*/
calculateProjection(destinationFrame, sourceFrame)
{
const pm = this.projectionMatrix;
sourceFrame = sourceFrame || destinationFrame;
pm.identity();
// TODO: make dest scale source
if (!this.root)
{
pm.a = 1 / destinationFrame.width * 2;
pm.d = 1 / destinationFrame.height * 2;
pm.tx = -1 - (sourceFrame.x * pm.a);
pm.ty = -1 - (sourceFrame.y * pm.d);
}
else
{
pm.a = 1 / destinationFrame.width * 2;
pm.d = -1 / destinationFrame.height * 2;
pm.tx = -1 - (sourceFrame.x * pm.a);
pm.ty = 1 - (sourceFrame.y * pm.d);
}
}
/**
* Resizes the texture to the specified width and height
*
* @param {number} width - the new width of the texture
* @param {number} height - the new height of the texture
*/
resize(width, height)
{
width = width | 0;
height = height | 0;
if (this.size.width === width && this.size.height === height)
{
return;
}
this.size.width = width;
this.size.height = height;
this.defaultFrame.width = width;
this.defaultFrame.height = height;
this.frameBuffer.resize(width * this.resolution, height * this.resolution);
const projectionFrame = this.frame || this.size;
this.calculateProjection(projectionFrame);
}
/**
* Destroys the render target.
*
*/
destroy()
{
this.frameBuffer.destroy();
this.frameBuffer = null;
this.texture = null;
}
}